1. Field of the Invention
The invention relates to an image processing device which performs image processing.
2. Background Art
In recent years, in-vehicle cameras have been developed and are becoming widespread for supporting driving. These cameras not only show a user an image, but also are provided with a function for automatically detecting a lane mark, or vehicles using imaging processing, and in which a function of preventing an accident of a vehicle departing from the lane mark, or a function of following a preceding vehicle has been developed. In general, in order to execute these two functions, radar equipment such as a mill wave radar, or a laser radar, and the in-vehicle camera are used. There is a problem of high cost since two types of sensors are used.
Therefore, a technology is required in which a function of executing a tracking control, and lane mark keeping is executed only using an image obtained from the camera. As a technology of performing the tracking control only using an image obtained from a camera, a method which is described in JP-A-2002-74598 has been proposed.
In the method, the width of a preceding vehicle on an image at a certain time t is obtained, and is registered as an amount of standard characteristics, the width of the preceding vehicle on the image which is obtained at a time t+N thereafter is obtained, and the speed of the vehicle is controlled so as to match the amount of standard characteristics. For example, when the width of the preceding vehicle on the image at time t is 20 pixels, and the width of the preceding vehicle on the image at time t+N is 25 pixels, it is possible to execute the tracking control by controlling the speed of the own vehicle to be lowered, since the own vehicle is close to the preceding vehicle.